Art of and means for effecting power transmission



3 Sheets-Sheet l A. H. ASPROOTH ET AL Filed Feb. 27, 1925 www July 3l,1928.

ART oF AND vMEANS FOR EFFECTING POWER TRANSMISSION July 31, 1928..1,678,798' 5.".

A. H. ASPROOTH ET AL.

ART OF- AND MEANS FOR EFFECTING POWER TRANSMISSION Filed Feb.4 27. 192ss sheets-sheet z Stroms,

July 31, 1928. l 1,678,798

lA. H. AsPRooTH ET AL RT OF' AND MEANS FOR EFFECTING POWER TRANSMISSIONFiled Feb. 27, 1923 3 Sheets-Sheet 3 I A TTORNEYS.

Patented July 31, 1928.

UNI-TED siA'rqEs PATENT. OFFICE.

AXEL HJ. ASPROOTH, OF BALTIMORE, MARYLAND, AND ALFONSO LEONI, OF vPHILA-DELPHIA, PENNSYLVANIA, ASSIGNORS TO ELECTRO-MOTIVE DEVICES, INC., 'OFPHILADELPHIA, PENNSYLVANIA, A CORPORATION Y OF NEW JERSEY.

.ABT OF .LAND MEANS FOR EFFECTING POWER TRANSMISSION.

Application aied'rebmary 27, 192e. serial No. 621,581.

This invention relates to ldriving mechanism for vehicles of lthe typefor use between a driving motor and a driven wheel and involving gearreduction provisions.

The planetary system of gearing., particularly that wherein the internalgear is stationary., has been more or less popular in gear reductionmechanism for electric driven vehicles on account of its centrality ofdrive and tcoinpactness combined with its range of speed reductions.

The conventional planetary gearing may be of the single or doublereduction type. In the former, and as is obvious, all tooth pressuresare balanced and hence the tendency towards twisting of the journalsunder driving stress is negligible. On the other hand, the toothpressures are not balanced in the conventional planetary gearing of thedouble reduction type, with the result that bending and cockingreactions aredevcloped and imposed upon the journals and the compoundplanet gears.

Manufacturers and designers are aware of this condition and have soughtto successfully combat it by employing eXtra heavy journals in an effortto secure a rigid assembly. The practicability of this expedient isdiscounted by the high frictions that eventually ensue and by the factthat under repeatedreversing the structure soon loses its rigidity.

The principal object of this invention is to provide driving mechanismprimarily intended for` electric driven vehicles wherein allobjectionable reactive forces are eliminated or balanced.

The invention is illustrated in the accompanying drawings wherein- Fig.1 is a view principally in section showing the practical embodiment ofthe invention in a driving axle construction.

Fig. 2 is a similar view.

Fig. 3 is an end view of the balanced planetary system.

Fig. 4 is a sectional view of a modified embodiment; and

Figs. 5 and 6 are detail views of the spiders.

A practical embodiment of the invention is illustrated in Fig. 1, whichshows the improved inal drive applied to a standard wheel constructiongenerally indicated at 25. The inner end of the wheel hub assembly isprovided with an axle carrying casing or .bracket 26, circumferentiallyenlarged at 27 to accommodate Jdie motor casing 28 to which it issecured, as at 29. The part 27 of the .axle casing constitutes a gearhousing and the wheel driving shaft 30 is centered therein by a, sleeveor hollow spindle 31 flared at its inner end and termina-ting in yaflange or collar 32 seated in a recess 33 in the gear housingto which it.is rigidly secured as by rivets 34. The motor or driving 5 shaft 35,piloted by bearings such as 36, is provided with axed pinion 37. Thepinion is centered with respect to the shaft by an accurately turnedbushing 38 interposed between it and the shaft and retained by lockingprovision 39. Splined to the wheel drivingl shaft 30 is a spider 40 ofrugged construction and whose arms 41 extend beyond the driving pinion37 and serve to support by means of bolts 42 a pair of rings 43 and 44in which are mounted journals 45 carrying the planet pinions 46, thejournals providing roller paths 47 for said pinions. The pinions 46co-operate with the driving pinion 37 and with an annular rack 48liXedly secured to the gear housing. The element 48 is in reality acompound or double rack, that is to say it is divided by an annularrecess 49 to form dual tracks 50 and 51. Similarly the planet gears arecompound elements, the part 52 which engages the driving pinion 37 beingaccommodated in the recess 49 and the'reduced ends or trunnion portions53 and 54 engaging the tracks 50 and 51.

In the modification, Fig. 2, the fixed gear element or annular rack isof I beam section, the medial portion 55 constituting the track for thetoothed portion 56 of the planet pinions, the toothed portions 57 and 58of the latter in engagement with the compound driving pinion 59 beingaccommodated on either side of the track 55. c

In the two constructions noted, elimination or balancing of objectionalreactive forces is afforded by maintenance of uniform pitch linecontact, or in other Words by symmetry of drive.

Fig. 4 illustrates a construction wherein the spider is vsupported andcentered by annular bearings, carried by the driving shaft. One way ofaccomplishing this is to provide a pair of spider sections or rings 60(lll fil

and Gl, whereof each is supported and centered by annular bearings, suchas 62 and 63. As shown in Figs. 5 and 6, the spider rings may havetelescopic provisions 64 and V65, which co-operate with bolts 66forzinterlooking purposes. The ring 60 constitutes the driving sectionand is riveted or otherwise secured to a hub element 67 iixedly securedto the wheel driving shaft.

Having described our invention, claim:-

1. A vehicle drive embodying a centered driving shaft, a centered drivenshaft, a standard hub, a motor casing, an intermediate housing having ashoulder opposite the motor casing, a bell shaped stiifening core orspindle for the housing, an internal gear rigidly secured between saidshoulder and the Vmotor casing, a driving spider splined to the drivenshaft, compound planets journaled in the spider in operative relationwith the internal gear, a driving pinion, and a bushing for centeringthe pinion to maintain uniformity of pitch line Contact. a

2. A vehicle drive embodying a centered driving shaft, a centered drivenshaft, a Y

standard hub, a motor casing, an intermediate housing having a.shoulder'opposite the motor vcasing, a bell shaped stiftening core orspindle for the housing, an internal gear rigidly Vsecured between saidshoulder and the motor casing, a driving spider splined to the drivenshaft, compound planets journaled in the spider in operative relationwith the internal gear, 'a driving pinion, and an annular bearingmounted on the driving shaft for centering the spider.

In testimony whereof we aliix our signatures. 1

AXEL HJ. Asrnoorn.` y

ALFoNso M. LEONI.

